Sirens Fall

This land comes into play tapped.
{t}: Add {g/u} to your mana pool.
Hideaway: When this land comes into play, look at the top 4 card of your library, choose one of those cards and exile it.
{t}{g/u}: If three more more lands entered the battlefield this turn you may cast the card exiled with Sirens Fall this turn for not cost.
There is more than one way to fall to your death.